1. Field
Aspects of the present invention relate to a thin film deposition apparatus, and more particularly, to a thin film deposition apparatus including a deposition blade so that a deposition material is not deposited on a nozzle unit during a deposition process.
2. Description of the Related Art
Organic light-emitting display devices include an anode, a cathode, and an emission layer. Organic light-emitting display devices may optionally include intermediate layers to achieve high light-emission efficiency. Examples of such intermediate layers include an electron injection layer, a hole transport layer, and a hole injection layer.
The anode, the cathode, the emission layer, and the intermediate layer may be formed via various methods, one of which is a deposition method. When an organic light-emitting display device is manufactured using the deposition method, a fine metal mask (FMM) is used. The FMM has a pattern that corresponds to a thin film to be formed on a substrate. The FMM is disposed to closely contact the substrate. A thin film material is deposited over the FMM in order to form the thin film having a desired pattern. In this regard, the size of the FMM has to be the same as that of the substrate. Thus, the size of the FMM has to be increased as the substrate becomes larger. However, it is neither straightforward to manufacture a large FMM nor to extend an FMM to be accurately aligned with a pattern.
Furthermore, a deposition method using a FMM has low deposition efficiency. Deposition efficiency refers to the ratio of a deposition material deposited on a substrate to the deposition material vaporized from a deposition source. The deposition method using a FMM has a deposition efficiency of about 32%. Also, in the deposition method using a FMM, about 68% of the deposition material that is not deposited on the substrate remains adhered to a thin film deposition apparatus. Thus, it is not straightforward to reuse the deposition material not deposited on the substrate.